Oh sure, any colored dope can be added to give some contrast. I use orange nitrate. If you have butyrate colors, just add a little bit to the nitrate. White, yellow etc, will contrast well.......If you use butyrate in the nitrate don't use more than about 10%. Butyrate is easier to find at the LHS but is no where near as stable as nitrate in the short term. The less the better... Best is finding some dry pigment and admixing dry. Maybe a local Art Supply store....

MonoKote iron. You'd have to play with amount of heat. You want to melt the dope a bit so that the veil sticks. But if you use your finger to rub the dope into the veil, you shouldn't have much trouble with iltfing. I brush a small area and then rub, and so forth until the sheet is set. I often use a paper towel as I rub to accelerate the drying and setting. It's just a technique of course; other techniques work also.

I assume that you will not spread the adhesive over the whole sheet, just the areas that bond. All the more reason to make sure the veil is well stuck to the sheet.